TY - JOUR
T1 - J1342+0928 supports the timeline in the Rh = ct cosmology
AU - Melia, Fulvio
N1 - Funding Information:
I am very grateful to the anonymous referee for his/her helpful comments and suggestions that have led to a significant improvement in the presentation of this manuscript. I am also grateful to Amherst College for its support through a John Woodruff Simpson Lectureship, and to Purple Mountain Observatory in Nanjing, China, for its hospitality while part of this work was being carried out.
PY - 2018
Y1 - 2018
N2 - Aims. The discovery of quasar J1342+0928 (z = 7.54) reinforces the time compression problem associated with the premature formation of structure in Λ cold dark matter (ΛCDM). Adopting the Planck parameters, we see this quasar barely 690 Myr after the big bang, no more than several hundred Myr after the transition from Pop III to Pop II star formation. Yet conventional astrophysics would tell us that a 10 M seed, created by a Pop II/III supernova, should have taken at least 820 Myr to grow via Eddington-limited accretion. This failure by ΛCDM constitutes one of its most serious challenges, requiring exotic “fixes”, such as anomalously high accretion rates, or the creation of enormously massive (∼105 M) seeds, neither of which is ever seen in the local Universe, or anywhere else for that matter. Indeed, to emphasize this point, J1342+0928 is seen to be accreting at about the Eddington rate, negating any attempt at explaining its unusually high mass due to such exotic means. In this paper, we aim to demonstrate that the discovery of this quasar instead strongly confirms the cosmological timeline predicted by the Rh = ct Universe. Methods. We assume conventional Eddington-limited accretion and the time versus redshift relation in this model to calculate when a seed needed to start growing as a function of its mass in order to reach the observed mass of J1342+0928 at z = 7.54. Results. Contrary to the tension created in the standard model by the appearance of this massive quasar so early in its history, we find that in the Rh = ct cosmology, a 10 M seed at z ∼ 15 (the start of the Epoch of Reionization at t ∼ 878 Myr) would have easily grown into an 8 × 108 M black hole at z = 7.54 (t ∼ 1.65 Gyr) via conventional Eddington-limited accretion.
AB - Aims. The discovery of quasar J1342+0928 (z = 7.54) reinforces the time compression problem associated with the premature formation of structure in Λ cold dark matter (ΛCDM). Adopting the Planck parameters, we see this quasar barely 690 Myr after the big bang, no more than several hundred Myr after the transition from Pop III to Pop II star formation. Yet conventional astrophysics would tell us that a 10 M seed, created by a Pop II/III supernova, should have taken at least 820 Myr to grow via Eddington-limited accretion. This failure by ΛCDM constitutes one of its most serious challenges, requiring exotic “fixes”, such as anomalously high accretion rates, or the creation of enormously massive (∼105 M) seeds, neither of which is ever seen in the local Universe, or anywhere else for that matter. Indeed, to emphasize this point, J1342+0928 is seen to be accreting at about the Eddington rate, negating any attempt at explaining its unusually high mass due to such exotic means. In this paper, we aim to demonstrate that the discovery of this quasar instead strongly confirms the cosmological timeline predicted by the Rh = ct Universe. Methods. We assume conventional Eddington-limited accretion and the time versus redshift relation in this model to calculate when a seed needed to start growing as a function of its mass in order to reach the observed mass of J1342+0928 at z = 7.54. Results. Contrary to the tension created in the standard model by the appearance of this massive quasar so early in its history, we find that in the Rh = ct cosmology, a 10 M seed at z ∼ 15 (the start of the Epoch of Reionization at t ∼ 878 Myr) would have easily grown into an 8 × 108 M black hole at z = 7.54 (t ∼ 1.65 Gyr) via conventional Eddington-limited accretion.
KW - Cosmology: observations
KW - Cosmology: theory
KW - Early Universe
KW - Galaxies: active
KW - Quasars: supermassive black holes
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U2 - 10.1051/0004-6361/201832752
DO - 10.1051/0004-6361/201832752
M3 - Article
AN - SCOPUS:85064412571
VL - 615
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
SN - 0004-6361
M1 - A113
ER -